Rated 5 out of 5 stars
Because of the recent eBay problems with potentially compromised passwords I changed mine and FF wouldn't remember the new one. I tried deleting the eBay login entries in the Password Manager (Saved Passwords) to start over, but FF still wouldn't present the dialogue to save the login details. After trying several other add-ons I read about this one and it's worked like a charm, solving the problem because it enabled me to enter the login details manually after which the autofill worked perfectly. Also it's very easy to use.
Many thanks to the developer! (contribution on it's way)
Using an older version of FF (3.6.28) on an older Mac running OS 10.4.11 (Tiger). Version of SPE installed = 2.6.4 (not the latest presumably because of my older version of FF)